Halogenized indigo compounds and process of making such bodies.



UNITED STATES PATENT OFFICE.

HENRY STALAY ARTHUR HOLT. OF LUDWIGSHAFEN-ONTHERHINE, GERMANY, AS-

SIGNOR T0 BADISCHE ANILIN & SODA FABBIK, OF LUD\VIGSHAFEN-ON-THE-RHINE,

GERMANYfA CORPORATION.

HALOGENIZED INDIGO COMPOUNDS AND PROCESS OF MAKING SUCH BODIES.

No Drawing.

Specification of Letters Patent.

Patented Oct. 29, 1912.

Application filed August 22, 1910. Serial No. 578,377.

To all whom it may concern:

Be it known that I, HENRY STALAY AR- THUR How, a subject of the King of England, residing at Germany, have invented new and useful Improvements in Halogenized Indigo Compounds and Processes of Making Such Bodies, ofwhich the following is a specification.

The specification of the application for Letters Patent Serial No. 5%,612 describes .the production of halogenated dehydroindiabsence of any compound capable of fixing hydrochloric acid. Instead of dehydroindigo, the corresponding indigo coloring matter itself can be used, if the halogen or the halogenizing agent be allowed to react until the color of the indigo has entirely, or almost entirely, disappeared and the reaction mass has assumed a yellow to yellowbrown color in consequence of the formation of the dehydroindigosalt.

The following examples will serve to illustrate further the nature of my invention, which, however, is not confined to these examples. The parts are by weight.

Example 1 2 Pass chlorin into a suspension of nineteen parts of dehydroindigo acetate in one hundred parts of glacial acetic acid (preferably while cooling), until the suspension contains a canary yellow powder. Analysis points to this being trichlor -dehydroindigo acetate. From the solution, preferably after air has been blown through it in order to remove the excess of chlorin, a more highly chlorinated dehydroindigo acetate can be precipitated by means of water. If less chlorin be emplo ed in this. example, less highly chlorinatec dehydroindigo acetates can be obtained. Instead of hy roindigo acetate, derivatives thereof Ludwigshafen-on-the-Rhine,

can be employed, for instance, from dibromdehydroindigoacetate there can be obtained in a similar manner dibrom-monoc hlorand dibrom-dichlor-dehydroindigo acetate. In this example, instead of glacial acetic acid, other reagent, such for instance as acetic anhydrid, trichlorbenzene, nitrobenzene, or carbon tetrachlorid, can be employed.

Example 2: Pass chlorin into asuspension of thirteen parts of dehydroindigo in thirty parts of nitrobenzene until the brown color of the dehydroindigo has disappeared and a yellow crystalline powder is obtained. Filter thisofi' and wash it with ether. It appears to be a mixture of trichlorand tetrachlor-dehydroindigo-hydrochlorid. In this example, insteadof nitrobenzene, other suspension agents can be employed.

Example 3: Pass chlorin into a suspen sion of thirteen parts of indigo in one hundred parts of nitrobenzene, while'stirring and cooling somewhat, until the blue mass is replaced by a yellow-brown solution containing a light yellow precipitate. Allow this to stand for a short time, remove the excess. of chlorin by blowing air through it, filter off the product, and Wash it with ether. It appears to be trichlor-dehydroindigo hydrochlorid. The part of the product which remains in the nitrobenzene can EXample,t: Si 1spend ten parts of 5.5

dibromindigo in one hundred parts of glacial acetic acid and pass chlorin into the suspension until the indigo has disappeared. Dilute with water the yellow-brown solution, from which considerable quantities of monochlor-l and dichlor-dibrom-dehydroindigo 'hydrochlorid have crystallized out. Filter off the precipitate, wash it, and dry it at a slightly elevated temperature." In

this example, the 5.5-dibromindigo can bereplaced by other halogen indigos, such for instance as 6.6'-dichlorindigo and 4.4'-di chlorindigo. Further the glacial acetic acid can be replaced by acetic anhydrid, or' by a mixture of the said acid and anhydrid, or other'organir: agents can be used. 2

Example 5: Suspend ten parts of indigo in from fifty, to seventy-five, parts of acetyl chlorid and, While at a temperature of zero 'centigrade, pass in from twelve to fourteen parts of chlorin until the indigo has disapt pea-red and a yellowish. brown solution coni taining yellow crystals is obtained. The product can be worked up either by-introj ducing it into'a mixture of ether and water, or by distilling off the acetyl chlorid in cacao. The product appears to be trichlordehydroindigo hydrochlorid. In this ex ample, instead of acetyl chlorid, phosphorus oxychlorid, or other chlorid, such for instance as sulfuryl chlorid, can be employed. \Vhen sult'uryl chlorid is used, more highly chlorinated derivatiies of dehydroindigo can be obtained containing for instance from seven to eightatomic proportions of chlorin, and these derivatives, on being converted into the corresponding indigo coloring inatters, part with the loosely combined chlorin atoms and give rise to tetrachlorindigo.

I Example 6: Suspend ten parts of indigo in seventy-five parts ofcarbon tetrachlorid and add,- gradually, at ordinary temperature, eighty parts of sulfuryl chlorid. After stirring for about five hours, the mass commences to turn green and after another ten hours the Whole consists of a brownish yellow solution from which considerable quantities of halogenated dehydroindigo hydrochlorid are separated out.

Now what I claim is 1. The process of producing halogenized indigo coloring matter by treating an indigo coloring matter with a halogenizing agent in the absence of a salt which combines with halogen hydrid and in the presence of an organic acid capable of yielding a salt with halogenized dehydroindigo, and then reducingthe halogenized dehydroindigo coloring matter into the corresponding halogenized indigo coloring matter.

i 2 In the production of halogenized in- 1 digo coloring matter the process which consists in treating a dehydroindigo salt which is free from sulfur with a halogenizing agent in the absence of a salt which neutralizes halogen hydrid.

3. In the production of halogenized indigo coloring matter the process which consists in treating an indigo coloring matter with a halogenizing agent gives rise to halogen in the absence of a salt which combine with halogen hydrid and in the presence of an organic acid capable of yielding a salt with halogenized dehydroindigo.

4. Iii-the production of halogenized indigo coloring matter the process which con sists in treating a dehydroindigo sat which is free from sulfur with a ,halogenizing agent in the absence of a salt which neutraL izes halogen hydrid and then reducing the halogenized dehydroindigo coloring matter into the corresponding halogenized indigo coloring matter.

5. In the production of halogenized indigo coloring matter the process which consists in treating indigo with a halogenizing' agent in the absence of a salt which coinbines with halogen hydrid and in the-presence of an organic acid capable of yielding a salt with halogenized dehydroindigo.

In testimony whereof I have hereunto set it y hand in the presence of two subscribing witnesses. I Y

ARTHUR HOLT. Witnesses: n

ERNEST G. EHRHARDT, ERNEST L. IVES. 

